Linux 绑定两块网卡

主要作用是避免单块网卡故障导致网络中断，通过双网卡提高可靠性

1、添加一块网卡

确保新添加的网卡与之前的网卡处于同一种网络模式，这里我们统一调整为NAT模式

并确认网卡添加成功

[root@localhost ~]# ip a
......
2: ens32: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:bd:2f:10 brd ff:ff:ff:ff:ff:ff
......
5: ens34: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:bd:2f:1a brd ff:ff:ff:ff:ff:ff
    inet6 fe80::cb56:a542:68b2:6152/64 scope link 
       valid_lft forever preferred_lft forever

我们原来网卡是ens32，新添加的位ens34

2、vi编辑两个网卡的配置文件

内容分别如下：
（若新添加的网卡没有配置文件则直接新建即可）

[root@localhost ~]# vi /etc/sysconfig/network-scripts/ifcfg-ens32 
内容如下：

TYPE=Ethernet
BOOTPROTO=none
DEVICE=ens32
ONBOOT=yes
USERCTL=no
MASTER=bond0
SLAVE=yes

[root@localhost ~]# vi /etc/sysconfig/network-scripts/ifcfg-ens34
内容如下：

TYPE=Ethernet
BOOTPROTO=none
DEVICE=ens34
ONBOOT=yes
USERCTL=no
MASTER=bond0
SLAVE=yes

 

3、配置bond0文件

vi直接添加该文件

[root@localhost ~]# vi /etc/sysconfig/network-scripts/ifcfg-bond0
内容如下：

TYPE=Ethernet
BOOTPROTO=none
DEVICE=bond0
ONBOOT=yes
USERCTL=no
IPADDR=192.168.200.150
PREFIX=24
GATEWAY=192.168.200.2
DNS1=114.114.114.114
NM_CONTROLLED=no

4、配置网卡绑定驱动模式并重启网络生效

[root@localhost ~]# vi /etc/modprobe.d/bond.conf
内容如下：

alias bond0 bonding
options bond0 miimon=100 mode=6

重启网络：
[root@localhost ~]# systemctl stop NetworkManager

[root@localhost ~]# systemctl disable NetworkManager
Removed symlink /etc/systemd/system/dbus-org.freedesktop.nm-dispatcher.service.
Removed symlink /etc/systemd/system/multi-user.target.wants/NetworkManager.service.
Removed symlink /etc/systemd/system/dbus-org.freedesktop.NetworkManager.service.

[root@localhost ~]# systemctl restart network

[root@localhost ~]# ifconfig
bond0: flags=5187<UP,BROADCAST,RUNNING,MASTER,MULTICAST>  mtu 1500
        inet 192.168.200.150  netmask 255.255.255.0  broadcast 192.168.200.255
        inet6 fe80::20c:29ff:febd:2f10  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:bd:2f:10  txqueuelen 1000  (Ethernet)
        RX packets 4  bytes 345 (345.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 36  bytes 4789 (4.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens32: flags=6211<UP,BROADCAST,RUNNING,SLAVE,MULTICAST>  mtu 1500
        ether 00:0c:29:bd:2f:10  txqueuelen 1000  (Ethernet)
        RX packets 92  bytes 23344 (22.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 110  bytes 14281 (13.9 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens34: flags=6211<UP,BROADCAST,RUNNING,SLAVE,MULTICAST>  mtu 1500
        ether 00:0c:29:bd:2f:1a  txqueuelen 1000  (Ethernet)
        RX packets 13  bytes 1434 (1.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 151  bytes 26298 (25.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

......

5、验证

我们可以在终端中执行 ping baidu.com 命令，然后通过vmware删除新添加的那块网卡，发现会短暂中断一个包后又恢复正常或者直接没有发现丢包，这说明自动进行了网卡的切换，确保了功能的正常不中断

[root@localhost ~]# ping baidu.com
PING baidu.com (110.242.68.66) 56(84) bytes of data.
64 bytes from 110.242.68.66 (110.242.68.66): icmp_seq=1 ttl=128 time=34.3 ms
64 bytes from 110.242.68.66 (110.242.68.66): icmp_seq=2 ttl=128 time=36.1 ms
64 bytes from 110.242.68.66 (110.242.68.66): icmp_seq=3 ttl=128 time=47.5 ms
64 bytes from 110.242.68.66 (110.242.68.66): icmp_seq=4 ttl=128 time=34.4 ms
64 bytes from 110.242.68.66 (110.242.68.66): icmp_seq=5 ttl=128 time=33.9 ms
64 bytes from 110.242.68.66 (110.242.68.66): icmp_seq=6 ttl=128 time=34.7 ms
64 bytes from 110.242.68.66 (110.242.68.66): icmp_seq=7 ttl=128 time=47.3 ms
64 bytes from 110.242.68.66 (110.242.68.66): icmp_seq=8 ttl=128 time=35.4 ms
......---------------------------------------------------------